<!DOCTYPE html>
<html lang="en-US">
<!--********************************************-->
<!--*       Generated from PreTeXt source      *-->
<!--*                                          *-->
<!--*         https://pretextbook.org          *-->
<!--*                                          *-->
<!--********************************************-->
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<meta name="robots" content="noindex, nofollow">
</head>
<body class="ignore-math">
<h3 class="heading"><span class="type">Paragraph</span></h3>
<p>Furthermore, you may face several ODEs containing several unknowns, for example</p>
<div class="displaymath process-math" data-contains-math-knowls="./knowl/eq1_3.html">
\begin{equation}
\begin{cases}
&amp;\frac{\textrm{d}u}{\textrm{d}x}=2v+u ,\\
&amp;\frac{\textrm{d}v}{\textrm{d}x}=2u.
\end{cases}\tag{1.1.2}
\end{equation}
</div>
<p class="continuation">Equation (<a href="" class="xref" data-knowl="./knowl/eq1_3.html" title="Equation 1.1.2">(1.1.2)</a>) has two equations and contains two unknowns <span class="process-math">\(u, v\text{,}\)</span> and it is called a system of ODEs.</p>
<span class="incontext"><a href="sec_1-intro.html#p-2" class="internal">in-context</a></span>
</body>
</html>
